If a player has been placed on optional assignment waivers, outright assignment waivers, or outright release waivers (all irrevocable), the club awarded the claim is based on W-L record regardless of league. If he's been placed on trade assignment waivers (revocable), teams in his own league have priority. Waiver requests are transmitted at 2:00PM each business day. (I assume that's Eastern Time.) If a request is made after 2:00PM, it's transmitted the following day. Every day is considered a business day during the season. During the off-season, weekends and several holidays aren't included as business days. During the off-season and during the first 30 days of the season, the previous year's W-L record is used to determine claim priority. Beginning with the 31st day of the season, the current year's W-L record is used. If teams making a claim have the same W-L record, the previous year's record is used as a tie-breaker. If two teams are still tied, MLB goes back a season further. Teams have about 48 hours to make a claim, so it's possible that a team better than the Brewers may have made a claim first. Where a player goes isn't officially decided until until 1:00 PM on the second business day after the waiver request is made. Designating a player for assignment allows a team to remove the player from its 40-man roster immediately while the waiver process sorts itself out. Here's a source that appears to be up to date as of this year.